The present invention concerns socket mounts, particularly printed circuit board contact elements used to mount electrical device-containing sockets to the circuit boards.
Burn-in sockets are generally soldered to the printed circuit boards. The solder electrically and mechanically secures the socket to the printed circuit board.
Burn-in is a semiconductor industry manufacturing process for screening out non-functional chips or devices. The chip is inserted into a socket (commonly referred to as a burn-in socket), this socket holds the chip in place while providing electrical continuity from the chip to a printed circuit board (PCB).
The burn-in socket (BIS) comes with contact pins. The length of the contact pin that protrudes from the bottom of the socket into the PCB for soldering is called a solder-tail. When a socket is de-soldered from a PCB, solder remnants are left on the solder-tail. These solder remnants increase the diameter of the contact pin making it difficult to reuse the socket by inserting the increased diameter contact pin in a new board.
There are at least three problems associated with soldering sockets to the printed circuit board. First, in order to remove the socket, the solder must be reheated. The reheating process may damage the socket reducing its reliability when reused. In addition, the reheating process is difficult to limit to the area of the socket to be removed, affecting adjacent sockets. Second, soldering may cause thermal stress which may lead to plastic deformation. Third, desoldering may cause solder bridging of solder remnants on the socket solder-tails. Solder remnants on the solder-tail also reduces the reliability if the socket is replaced.
The number of contact pins per socket can range from as few as 10 contact pins to 1500 or more contact pins. It is critical for the contact pins to remain straight so that they align with the holes in the PCB. After the burn-in socket is removed from the PCB, the contact pins may become bent or misaligned due to reheating or solder remnants on the socket solder-tail. Lastly, the cost of wave soldering equipment is high and processing lead times to replace a socket may be long.
Thus, there is a need for a socket mount that provides secure electrical connectivity between sockets and printed circuit boards without damage caused to the socket and adjacent sockets by reheating of solder socket connections. There is also a need for a simplified mounting and removal process for sockets that reduces the long lead times encountered with soldering operations.